This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A193746 #13 Aug 27 2020 05:41:21
%S A193746 1,2,7,5,311,434,42799,90075,12345679,34867844,6140565047,1695421,
%T A193746 4696537119847,20088655029078,5124095576030431,25657845139503479,
%U A193746 7563707819165039903,43404581642184336392,14523213296398891966759
%N A193746 Smallest k such that k*n^2 +1 is an n-th power.
%e A193746 a(9) = 12345679 because 12345679*9^2+1 = 1000000000 = 10^9.
%t A193746 a={}; Do[k = 2;While[ !IntegerQ[(k^n - 1)/n^2], k++ ]; AppendTo[a,(k^n-1)/n^2], {n, 1, 20}]; a
%o A193746 (PARI) a(n)=my(k);while(!ispower(k++*n^2+1,n),);k \\ _Charles R Greathouse IV_, May 15 2013
%Y A193746 Cf. A076943.
%K A193746 nonn
%O A193746 1,2
%A A193746 _Michel Lagneau_, Aug 03 2011